The goal of this research proposal is to identify relationships that exist between specific genetic markers, immune responses to injury and infection (sepsis), and post injury clinical outcomes. Specifically, we will investigate the clinical impact of mutations involved in the innate immune response, which likely influence host response. To accomplish this goal we will collect and analyze data from )atients with acute thermal injury, the most quantitative inflammatory stimulus experienced by humans. In addition, we propose to further characterize the immunologic response parameters to injury and infection, and their role in complicated sepsis. In this way, we will identify parameters associated with unfavorable clinical outcomes, and determine how these parameters differ among individuals with different genotypes. We propose to 1) evaluate associations between candidate SNPs within the NOD2/RIP2 signaling pathway and clinical outcome following burn injury, 2) evaluate the functional effects of alternate alleles at candidate SNPs; finally 3), we will use genetically engineered animal models to determine whether mutations in the NOD2 or RIP2 genes alter myocardial signal transduction mechanisms shown to play a role in myocardial inflammation/dysfunction after burn trauma. These approaches should allow us to evaluate more extensively clinically relevant interactions between specific genetic polymorphisms, the cellular expression of immune mediators, and burn-induced immune dysfunction. The proposed research should uncover genetic and/or acute immune-inflammatory parameters that identify patients who are at "high risk" and could as a result make possible the targeted design of pharmacologic intervention strategies that will inhibit the toxic effects of LPS and other bacterial pathogen components without paralyzing the host immunity of patients with thermal injury.